According to Nigerian Media outlets , the attackers first detonated an explosive device at St. Francis Parish in Owo, Ondo State, in the southwest of the country. Newspapers -The Punch said they then opened fire on the congregation.

Ondo State Governor Arakunrin Oluwarotimi Akeredolu, who visited the scene of the attack and the injured in hospital, described the incident as a “major massacre“.

“It is really sad that unknown gunmen attacked a church while Holy Mass was in progress,” said Augustine Ikwu, spokesman for the Catholic Church in Nigeria. He said the bishop and priests of the parish survived the attack unharmed.

A doctor at a hospital in Owo told Reuters news agency that at least 50 bodies were taken to two hospitals in the city because of the attack. The doctor, who declined to be identified because he is not authorized to speak to the press, also said blood donations will be needed to treat the injured.

President Muhammadu Buhari condemned the attack, calling it “heinous,” and the Vatican said Pope Francis was praying for the victims.

Such attacks on places of worship are rare in southwestern Nigeria. An investigation has been launched, according to Funmilayo Ibukun Odunlami, a police spokesman in Ondo State.